Thixotropic liquid sanitary cleanser and its uses

ABSTRACT

The invention relates to a liquid cleanser with thixotrope properties and its use as a liquid sanitary cleaning agent, in particular for cleaning toilets, washbowls, shower cabinets, shower tubs and swimming pools as well as kitchen sinks. 
     The liquid cleanser contains along with usual cleanser additives in aqueous solution as a surface-active agent one or more compounds selected from the group of alkylamidobetaines, alkylaminobetaines, alkylbetaines, alkyl polyglycol ether carboxylic acids and/or fatty alcohol ethoxylates in mixture with pyrogenic silicic acid and at least one organic acid selected from the group of citric acid, lactic acid, tartaric acid, maleic acid, malic acid, glutaric acid, adipic acid, acetic acid and formic acid.

This invention relates to a liquid cleanser with thixotrope propertieswhich contains a surface-active agent and an organic acid along withusual cleanser additives in aqueous solution, and to its use as a liquidsanitary cleaning agent, in particular for cleaning toilets, washbowls,shower cabinets, shower tubs and swimming pools as well as kitchensinks.

Conventional acidic liquid toilet cleaning agents contain along withsurface-active agents substantially organic acids (e.g. formic acid,acetic acid or citric acid) or inorganic acids (e.g. phosphoric acid orhydrochloric acid) and polysaccharides as thickening agents as well asusual further additives such as stabilizers, dyes and scents.

Known acidic liquid toilet cleaning agents are effective for example inremoving lime and urine deposits as well as in destroying bacteria andbad smells which form predominantly on the lime and urine deposits.

The most frequently used relatively strong acids, such as hydrochloricacid, phosphoric acid and formic acid, belong to water danger class 1.Phosphoric acid furthermore has a eutrophic effect. Hydrochloric acidand formic acid are considered strong irritants for the eyes,respiratory tract and mucous membranes so that liquid toilet cleanserscontaining these acids can already be recognized by their keen and sharpsmell. The stated strong acids are furthermore very difficult toperfume. Inorganic acids and formic acid therefore involve a potentialdanger because of their corrosive effect and should not be used forhousehold cleaning agents if possible.

The thickening agents contained in known toilet cleaning agents areintended to increase the viscosity of the cleaning agent and ensure thatthe acidic cleaning solution can act as long as possible on the verticalsurfaces of a toilet bowl.

However, the viscosity of a toilet cleanser cannot be increased at will,the lime solvent power decreasing with increasing viscosity as a resultof diffusion problems of its lime-dissolving components on the toiletsurface to be treated, and problems furthermore occurring with respectto the distribution of the cleanser, which becomes more difficult withincreasing viscosity. This limits the exposure time and the exposureconcentration of the lime-dissolving components of the toilet cleansersand thus their cleaning power, in particular their lime solvent power(LSP).

The problem of the invention was therefore to develop an improved liquidcleanser which has a higher cleaning power, in particular improved limesolvent power, while using weaker, less polluting acids without theabovementioned problems occurring.

It was found that this problem can be solved by considerably improvingthe adhesion of a sufficiently thick cleaning film to the surface to becleaned by using pyrogenic silicic acid, which in combination withcertain organic acids and surface-active agents gives the liquidcleaning agent thixotrope properties.

It was surprisingly found in particular that thixotropic acidic aqueouscleaning solutions (containing organic carboxylic acids) with clearlyhigher lime solvent power can be obtained with various surface-activeagents, based on the same active content, and pyrogenic silicic acid.

The subject-matter of the invention is a liquid cleanser with thixotropeproperties which contains a surface-active agent and an organic acidalong with usual cleanser additives in aqueous solution, characterizedin that it contains as a surface-active agent one or more compoundsselected from the group of alkylamidobetaines, alkylaminobetaines,alkylbetaines, alkyl polyglycol ether carboxylic acids and/or fattyalcohol ethoxylates in mixture with pyrogenic silicic acid and at leastone organic acid selected from the group of citric acid, lactic acid,tartaric acid, maleic acid, malic acid, glutaric acid, adipic acid,acetic acid and formic acid.

The surface-active agents to be used according to the invention are oneswhose alkyl group or fatty acid group is a saturated or unsaturatedalkyl group with 10 to 18, preferable 12 to 14, carbon atoms, and thealkyl polyglycol ether carboxylic acids and/or fatty alcohol ethoxylatesused as surface-active agents preferably contain 2 to 15, in particular3 to 7, specifically 3, ethylene oxide units per molecule.

An especially advantageous surface-active agent is alkylamidopropylbetaine, which is preferably used in 30% form.

Of the abovementioned organic acids, citric acid is especiallyadvantageous.

The pyrogenic silicic acid preferably used according to the invention isAerosil, in particular a type 200 one, and/or Cab-o-Sil, in particular atype M5 one.

The inventive liquid cleanser can additionally contain glycol andoptionally one or more preservatives, in particular benzoic acid,optionally one or more usual perfume oils and/or optionally one or moreusual dyes.

The inventive cleanser preferably contains the pyrogenic silicic acid ina quantity of 1.0 to 5.0%, specifically 1.8 to 2.5%, based on the totalweight of the cleanser.

The organic acid is preferably contained in the inventive cleanser in aquantity of 1 to 40%, in particular 5 to 15%, based on the total weightof the cleanser.

The inventive cleanser preferably contains the abovementionedsurface-active agent in a quantity of 0.5 to 5.0%, in particular 1.8 to2.5%, based on the total weight of the cleanser.

The glycol, which can be contained in the inventive cleanser as anoptional component, preferably exists in a quantity of 1 to 10%, inparticular 1.5 to 5%, based on the total weight of the cleanser.

If the inventive cleanser contains a preservative and optionally aperfume oil and optionally a dye, these components are preferablypresent in a quantity of 0.2 to 1.0% (preservative) and a total quantityof 0 to 2%, in particular up to 0.5% (perfume and dye), based on thetotal weight of the cleanser in each case.

If the inventive cleanser contains a fatty alcohol ethoxylate as asurface-active agent, this is preferably one with an ethylene oxidecontent of 2 to 12 mol, preferably 3 mol, which is present in a quantityof preferably 0.1 to 2%, in particular 0.5 to 1%, based on the totalweight of the cleanser.

An especially preferred inventive cleanser has the followingcomposition, based on the total weight of the cleanser:

about 2.2% pyrogenic silicic acid

about 2.0% glycol

about 0.3% preservative (preferably benzoic acid)

about 7.0% citric acid

about 2.0% alkylamidopropyl betaine (30%)

about 0.5% perfume oil and dye

balance water.

According to a further aspect the present invention relates to the useof the above-described cleanser as a liquid sanitary cleaning agent, inparticular for cleaning toilets, washbowls, shower cabinets, shower tubsand swimming pools as well as sinks in kitchens and labs.

With the inventive liquid cleaning agent one can increase the limesolvent power (LSP) by approx. 20% to 50% over toilet cleansers on themarket, as indicated by the following survey of LSP values which weredetermined by the method of quality recommendation for acidic toiletcleansers (of the Industrieverband Putz- and Pflegemittel e.V. in theversion of 1993) and classified as follows:

LSP>1.3=very good

LSP 0-7-1.3=satisfactory

LSP<0.7=inadequate

Comparison of LSP values of inventive cleansers and prior art cleansers

a) Inventive cleansers

    ______________________________________    Inventive cleanser with                           LSP value 1.44    abovementioned composition                           (very good)    Inventive cleanser with                           LSP value 1.71    same composition as above but                           (very good)    with alkylbetaine instead    of alkylamidopropyl betaine    Inventive cleanser with                           LSP value 1.91    same composition as above but                           (very good)    with alkyl polyglycol ether    carboxylic acid instead of    alkylamidopropyl betaine    ______________________________________

b) Comparable values for commercial products (liquid toilet cleansersbased on organic carboxylic acid with the exception of formic acid):

    ______________________________________    WC-frisch        LSP value 1.13 (satisfactory)    00 Plus Formel   LSP value 1.05 (satisfactory)    Frosch Essigreiniger                     LSP value 1.21 (satisfactory)    Tarax            LSP value 1.11 (satisfactory)    WC Ente, green   LSP value 1.22 (satisfactory)    Clinar           LSP value 0.98 (satisfactory)    ______________________________________

The inventive liquid cleanser thus has clearly improved LSP values overthe prior art, which were unforeseeable for the expert in the field.This is presumably due to the fact that the liquid no longer runs awayfrom the vertical surfaces during cleaning so that the exposure time andexposure concentration of the lime solvents is clearly increased whilethe diffusion of lime solvent on the surface to be treated issimultaneously improved.

Conversely, if limited demands are made on lime solvent power theconcentration of lime-dissolving agent can be clearly reduced and theenvironmental acceptability of the inventive liquid cleanser therebyimproved further, or stronger lime-dissolving acids can be used in lowerconcentration with environmental acceptability still being sufficient.

The inventive liquid cleanser with thixotrope properties can expedientlybe applied uniformly to the surface to be cleaned from a spray containerwith a spherical spray head having preferably four holes disposed eachperpendicular thereon. The inventive liquid cleanser becomes temporarilythinner by being sprayed and assumes a thicker consistency again whenhitting the surface to be cleaned, so that the inventive liquid cleansercan be applied to the surface to be cleaned in a better-sticking,thicker layer without the abovementioned problems with respect todistribution and diffusion properties occurring.

I claim:
 1. A liquid cleanser with thixotrope properties which containsa surface-active agent and an organic acid in an aqueous solution,consisting essentially of about 0.5 to 5 wt. % of a surface-active agentof one or more compounds selected from the group consisting ofalkylamidobetaines, alkylaminobetaines, alkylbetaines, alkyl polyglycolether carboxylic acids and fatty alcohol ethoxylates in mixture withabout 1.0 to about 5 wt. % of pyrogenic silicic acid about 1 to 40 wt. %of at least one organic acid selected from the group consisting ofcitric acid, lactic acid, tartaric acid, maleic acid, malic acid,glutaric acid, adipic acid, acetic acid and formic acid, and benzoicacid as a preservative.
 2. The cleanser of claim 1, wherein the alkylgroup or fatty acid group of the surface-active agents is a saturated orunsaturated alkyl group with 10 to 18 carbon atoms.
 3. The cleanser ofclaim 2, wherein the surface active agents selected from the groupconsisting of alkyl polyglycol ether carboxylic acids and fatty alcoholethoxylates have 2 to 15 ethylene oxide units per molecule.
 4. Thecleanser of claim 3, wherein the surface-active agent it contains isalkylamidopropyl betaine.
 5. The cleanser of claim 4, wherein theorganic acid it contains is citric acid.
 6. The cleanser of claim 5,wherein the pyrogenic silicic acid it contains is selected from thegroup consisting of Aerosil.
 7. The cleanser of claim 6, wherein itadditionally contains glycol, a preservative, a perfume oil and a dye.8. The cleanser of claim 7 wherein the preservative is benzoic acid. 9.The cleanser of claim 7 wherein it contains pyrogenic silicic acid in aquantity of 1.8 to 2.5%, based on the total weight of the cleanser. 10.The cleanser of claim 9 wherein it contains the organic acid in aquantity of 5 to 15% based on the total weight of the cleanser.
 11. Thecleanser of claim 10, wherein it contains the surface-active agent in aquantity of 1.8 to 2.5% based on the total weight of the cleanser. 12.The cleanser of claim 11, wherein it contains glycol in a quantity of 1to 10% based on the total weight of the cleanser.
 13. The cleanser ofclaim 12, wherein it contains the preservative benzoic acid, in aquantity of 0.2 to 1% perfume oil and dye in a total quantity of 0 to 2%based on the total weight of the cleanser.
 14. The cleanser of claim 13,wherein it contains a fatty alcohol ethoxylate with an ethylene oxidecontent of 2 to 12 mol in a quantity of 0.1 to 2% based on the totalweight of the cleanser.
 15. The cleanser of claim 14, wherein thecomposition of said cleanser (based on the total weight of the cleanser)is:about 2.2% pyrogenic silicic acid about 2.0% glycol about 0.3%preservative about 7.0% citric acid about 2.0% alkylamidopropyl betaine(30%) about 0.5% perfume oil and dye balance water.
 16. Use of thecleanser of claim 1 as a liquid sanitary cleaning agent for cleaningtoilets.
 17. Use of the liquid cleanser of claim 1 for cleaningwashbowls, shower cabinets, shower tubs and swimming pools as well askitchen sinks.